Electropneumatic brake.



W. V. TURNER.

ELECTROPNEUMATIC BRAKE.

APPLICATION FILED our. 3. 1914.

1 314,61 6. Patented Feb. 6, 1917.

INVENTOR Att'y.

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WALTER V. TURNER, 0F EDG-EVV'OOD, PENNS YLVANIA ASSIGNOR TO THE WESTING-HOUSE AIR BRAKE COMPANY, OF WILTEEBDING, PENNSYLVANIA, A CORPORATION OFPENNSYLVANIA.

ELECTROPNEUMATIC BRAKE.

Specification of Letters Patent.

Patented Feb. 6, 1917.

Application filed October 3, 1914. Serial No. 864,874.

To all whom itmay concern,

Be it known that I, WALTER V. TURNER, a citizen of the, United States,residing at Edgewood, in the county of Allegheny and State ofPennsylvania, have invented new and useful Improvements invElectropneumatic Brakes, of which the following is a specification.

This invention relates to electro-pneumatic brakes, and moreparticularly to an equipment in which the brakes are applied byelectrically venting fluid from the brake pipe.

The principal object of my invention is to provide means for limitingthe rate of reduction in brake pipe pressure'which can be made by theelectrically controlled means.

In the accompanying drawing, the single figure is a diagrammatic viewpartly in section, of an electro-pneumatic brake equipment for a car,with my improvement applied thereto.

As shown in the drawing, the brake equipment may comprise an equalizingor triple valve device 1, having the usual piston chamber 2 connected bypassage 3 to brake pipe 4 and containing piston5 and having valvechamber 6 connected by pipe 7 to auxiliary reservoir 8 and containingmain valve 9 and graduating valve 10 adapted to be actuated by piston 5.

The main valve seat is provided with the usual brake cylinder port 11connectedby pipe 12 to brake cylinder 13 and the slide valve 9 isprovided with cavity 14 for connecting brake cylinder port 11 withexhaust port 15 in release position.

According to my invention, the circuit of the magnet 18 is controlled bya switch 22,

contained in casing 33 and adapted to bridge contacts 23 and 24 in thecircuit wire .25. The switch 22 is carried by the stem 26 of a piston 27having a chamber 28 at one side preferably connected to a reservoir 29by passage 30, and having chamber 31 at the opposite side connected tobrake pipe 4.

When the fluid pressures on opposite sides of the piston 27 aresubstantially equalized, a spring 32 yieldingly maintains the pistonseated toward the chamber 28, with the switch 22 in closed position.

In order. to insure the seating of switch 22 when piston 27 is seated,the switch may the switchcasing 33 and thence through a small equalizingport 35 to chamber 28, also charging the reservoir 29 through passage30. The opposing fluid pressures on piston 27 being equalized, thespring 32 maintains the parts with switch 22 closed. If it is desired toapply the brakes electrically, current is supplied to the circuit wire25, so that the magnet 18 on each car of the train is energized. Thevalve 19 is then actuated by the magnet 18 to open communication forventing fluid from the brake pipe through passages 20-and 21 .tothebrake cylinder. The reduction in brake pipe pressure thus effectedcauses movement of the triple valves to service application position anda brake application is thenproduced in the usual manner. If the rate ofreduction in brake pipe pressure does not exceed the desired degree,then the equalizing port 35 is of sulficient size to maintainequalization of fluid pressures on the piston 27 by back flow from thereservoir29to the brake pipe. If, however, the rate of reduction shouldexceed the thereupon} deenergized and'the valves 19 are closed, so thatfurther venting offluidfrom the brake pipe is prevented. If the rate ofreduction in brake pipe pressure now becomes reduced so as to permit thefluid pressures on the piston 27 to equalize, the switch 22 will againclose, and should the operator still have the brake valve in applicationposition, the magnets 18 will be again energized to eflect a furtherventing of fluid from the brake pipe, but the operation of the switch 22will again prevent the rate of reduction from exceeding thepredetermined maximum, so that undesired movement of the triple valvesto emergency position will be prevented. 1 Having now described myinvention what I claim as new and desire to secure by Letters Patent, isp 1. In an electropneumatic brake, the combination with an electricallycontrolled valve for venting fluid from the brake pipe to effect anapplication of the brakes, of a switch device normally closing theelectric circuit of said valve during an application of the brakes andadapted to open said circuit upon the rate of reduction in brake pipepressure exceeding a predetermined deree. g 2. In an electro-pneumaticbrake, the COIH- bination with a brake pipe and an equalizing valvedevice operated by a reduction in brake pipe pressure for eiiecting anapplication of the brakes, of a magnet valve device for venting fluidfrom the brake pipe brake pipe to effect an application of the brakes, aswitch inthe control circuit of said valve and a piston normally holdingsaid switch closed during an application of the brakes and operated byfluid under pressure when the rate of brake pipe reduction exceeds apredetermined limit for actuating said switch to open the controlcircuit.

In testimony whereof I have hereunto set my hand.

WALTER V. TURNER. \Vitnesses A. M. CLEMEN'rs, S. W. KEEPER.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, D. G.

